The present invention relates to a sheet puncher to punch sheets, sheet finisher equipped with the sheet puncher and image forming apparatus having the sheet puncher.
Many image forming apparatus are equipped with the sheet finisher to conduct the finish processing such as the sorting, grouping, staple processing, and punch processing on sheets after image formation.
Many sheet finisher have the sheet puncher arranged along a conveying path to an sheet delivery section, and are structured in such a manner that the sheet which is being conveyed is temporarily stopped and punching processing is conducted. Further, in the punch processing, because it is required that a hole is provided at the correct position in the sheet, the alignment of the sheets is conducted prior to the punch processing (for example, Japanese Tokkaihei No. 6-56334).
The conventional sheet puncher is arranged along the conveying path, and for the punch processing, the conveying of the sheet is temporarily stopped. Accordingly, there is a problem that the processing speed of the image forming apparatus or the sheet finisher as an auxiliary apparatus of the image forming apparatus is lowered. Particularly, when the alignment processing of the sheet exists, the processing speed is further lowered. Then, when the processing speed is increased, there is a problem that the punching position becomes incorrect, and results in a trouble for the filing.
The present invention solves the above problem in the sheet puncher, sheet finisher equipped with the sheet puncher and image forming apparatus and the object of the present invention is to provide the sheet puncher by which the high speed punch processing can be conducted, and the hole can be punched at the correct position, sheet finisher and image forming apparatus.
The object of the preset invention is attained by any one of the following structures (1)-(8).
(1) A sheet puncher which is characterized in that: it is provided with; a reversal conveying section having a displaceable stopping member by which a sheet is stopped at a predetermined position, and punching means; a conveying-in and conveying-out section having a conveying-in means and conveying-out means by which the sheet is conveyed from a main conveying path into the reversal conveying section, and the sheet is conveyed out from reversal conveying section to the main conveying path, wherein the sheet is conveyed into the reversal conveying section by the conveying-in means, and after it is stopped at the predetermined position by the stopping member, it is punch processed by the punch means, and the conveying direction is reversed by the stopping member and the sheet is carried from the reversal conveying section by the conveying-out means.
(2) A sheet puncher according to (1), wherein the reversal conveying section has an alignment means, and after an alignment processing is conducted by the alignment means, the punch processing is conducted.
(3) A sheet puncher according to either one of (1) or (2), wherein the conveying-in and conveying-out section have a conveying-in path, conveying-out path, and guiding means, wherein the guiding means guides the conveying-in direction trailing edge of the sheet from the conveying-in path to the conveying-out path after the sheet is stopped by the stopping member.
(4) A sheet puncher according to any one of (1)-(3), wherein when the preceding sheet exists in the reversal conveying section, and after the conveying-in direction trailing edge of the preceding sheet is guided to the conveying-out path, the conveying-in means conveys the succeeding sheet into the reversal conveying section.
(5) A sheet puncher according to (3), wherein the stopping member is displaced such that the conveying-in direction trailing edge of the sheet is moved to the conveying-out path, and the punching means conducts the punch processing after the displacement of the stopping member.
(6) A sheet puncher according to any one of (1)-(5), wherein the punching means is displaced in according to the sheet size.
(7) A sheet finisher is characterized in that it has a sheet puncher according to any one of (1)-(6).
(8) An image forming apparatus is characterized in that it has a sheet puncher according to any one of (1)-(6).